Water-tube boiler



United StatesA Patent O 3,195,516 WATER-TUBE BOILER Heinrich Vorkaul, Davoser Strasse 2b, Berlin- Schmargendorf, Germany Filed June 27, 1961, Ser. No. 120,050 Claims priority, application Germany, .lluly d, 1960, V 18,926; Sept. 21, 1960, V 19,376 4 Claims. (Cl. 122-235) The invention relates to a water-tube boiler. In particular the invention relates to a type of such boilers which comprise tubes extending from a lower distributor to an upper collector, and being exposed to a radiant heat over a portion of their length. Other tubes, bent U-shaped and projecting into the current of the combustion gases, extend from and open again into the rst mentioned tubes and are shielded against radiation from the furnace by still other tubular members.

The invention aims to simplify the structure of the mentioned type of boilers and to reduce the space required by heating surfaces whereby, for the same steam output, a substantial saving of material and labor is achieved in comparison to the conventional boilers.

lt is another object of the invention to provide a structure whereby through the connection of a larger number of parallel U-shaped, serpentine tubes, a higher cooling effect is obtained. In this respect it has been found that the serpentine tubes will be cooled the more efficiently the greater the amount of steam created in the tube portions which precede the serpentine tubes, inasmuch as thereby the speed of the steam-water mixture will be acceleratcd and the distribution of the mixture among the U-shaped serpentine tubes, which are connected in parailel, will be improved.

It is still another object of the invention to provide a boiler of the mentioned type in which the U-shaped serpentine tubes, which project into the current of the combustion gases, extend from tubes which screen the serpentine tubes against radiation from the furnace. In such a structure special distributors and collectors become unnecessary for the evaporating heating surfaces connected in succession to the furnace, and the U-shaped serpentine tubes can be arranged horizontally whereby much space is saved in the gas llue. The increased steam production in the heating tubes which precede the serpentine tubes causes a high buoyancy eiect which insures a cooling lof the serpentine tubes under all conditions of operation.

in order to ensure the water circulation through the U-shaped serpentine tubes, it is furthermore proposed to provide a throttle between the entrances and outlets of the serpentine tubes in the tube from which the serpentine tubes extend. The steam contained in the rising steam-water mixture streams upwards through such throttle whereas the water will be compelled to enter the serpentine tubes. It is of high importance that the openings of the U-shaped serpentine tubes into the tubes from which they project are located below the water level of the separator drum as otherwise the water circulation in the serpentine tubes will be impaired. A further improvement of the water circulation can be obtained by the arrangement of return pipes and/or steam transfer pipes of a kind well known in the art. Such return pipes lead down- Wards from the collector to the distributor of the tubes which carry the U-shaped serpentine tubes, whereas the 3,195,516 Patented July 20, 1965 ICC steam transfer tubes conduct the steam directly from the collector to the separator drum.

Further objects and details of the invention wil be apparent from the description given hereinafter and accompanying drawing illustrating sseveral embodiments thereof by way of example.

ln the drawing:

FIG. l shows a boiler of the invention in front elevational section on the line l-l in FIG. 2;

FIG. 2 is a side-elevational sectional view of the boiler of FIG. l taken on the line IL-II; and

FlG. 3 shows a detail of the boiler in a sectional plan View taken on line Ill-III in FIG l.

The drawing shows a boiler of the invention having a flue located above the furnace and passed by the combustion gases in a horizontal direction.

The water-tube boiler illustrated includes an insulating brickwork shell conventionally shown at 51 in FIG. 2, and has a carrying framework which is formed by vertical downcomers 31, return pipes 31', longitudinal distributors 32, transverse distributors 32 and 32, longitudinal collectors 33, transverse collector 33 and a drum 34. The front wall and ceiling tubes 35 and the rear wall tubes 3d of the furnace extend from the transverse distributors 32 and 32, respectively. The furnace is furthermore bounded by groups of juxtaposed vertical side wall tubes 33 and 39 which, over a shorter distance of the length of the furnace, extend straight upwards from the longitudinal distributors 32 to the collectors thereabove. Gver the remainder of the length of the furnace there are groups of side wall tubes 38' and 39 which in a plane somewhat higher than half the height of the boiler, are bent approximately horizontal so as to cross the boiler space with portions 38" and 39 and to further extend vertically with portions 38 and 39" upwards to the collectors 33 on the sides opposite to those on which they are connected to their longitudinal distributors 32. It will be noticed that the tubes 38 are located each between two tubes 39 so that in the plane of the bent portions 33 and 39" a closed ceiling is formed above which a horizontal flue extends. U-shaped serpentine tubes are arranged in the flue 55 constituting a heating surface 49 in connection with the tube portions 38" and another heating surface 40' in connection with the tube portions 39 so that the sets of tubes of the heating surface 40 alternate and interengage with the sets of tubes of the surface 40'. Owing to this arrangement the total length of tubes exposed to radiation is increased and thus the evaporation in these tubes is intensified wherefrom a higher speed of ow results in these tubes and consequently a higher cooling effect. Simultaneously it becomes possible to connect a larger number of serpentine tubes to each side wall tube whereby an important increase of the heating surface in a very relatively small space is obtained. The increase of the length of tubes heated by radiation increases the pumping effect in these tubes.

As shown in FIG. 3, a throttling disc 113 having an opening 114 is inserted in the tube portions 38" and 39 between the entrances and exits of the serpentine tubes 40 and 40 to divert the flow of fluid from the tube portions to the serpentine tubes.

It will be apparent to those skilled in the art that modifications and alterations of the structure illustrated and described can be made without departure from the essence-and spirit of my invention which for that reason v shall not be limited but by the scope of the appended claims. Y v

I claim: v 1. In a Water tube boiler, in combination: (a) shell means defining a boilerspace therein. said shell means having a bottom portion, a top portion, and two horizontally spaced opposite side portions connecting said bottom portion andsaid top portion;r

the other side portion of said shell means, and a third portion of each tube extending upward from `said second portion along said other side portion to connect with said collector system,

(2) the tubes of each set being aligned with the interstices in the other set; Y (d) horizontally extending yceiling 4means dividing said boiler space into a furnace space below said ceiling means and a ue space above said ceiling means, said second tubev portions constituting elements of said ceiling means; Y

(e) a plurality of U-shaped serpentine tubes associatedV with respective heating tubes of said two sets, said serpentine tubes yextending in respective parallel vertical planes in said ue space, Y

(l) eachserpentine tube having an entrance por- Y ytion'and an exit portion, said portions being Y vertically spaced Vfrom each other and connected to the vthird portionfof the associated heating tube, Y Y Y l (2) the serpentine tubesy associated with each set of heating tubes being horizontally and vertically space and said ue space having respective portions'l `same l said distributor system to said collector system, (2) the tubes of a second group of juxtaposed heating tubes in each set having each three 1onv gitudinally consecutive portions, Y (3) a first portion extending upward from said distributing system, (4) a second portion extendingy horizontally across said furnace space toward the rst portions of the ytubes of the second group in the other set, and Y (5) a thirdportion extending upward from said f second portion to connect with said rdistributor v system, Y

(6) thev second portions ofy both sets being juxta,

posed to constitute` said partition; (f) a plurality of U-shaped serpentine tubes in said flue space, said serpentine tubes each extending in a l respective vertical planeand having'two end portions vertically yspaced from each other and connected to a respective one of'said third portions; and (g). diverting means lin each of said third portions'be- 'tween the, end portions of the connected serpentine "tube for ydiverting uid from saidf 'heating tubes to saidserpentine tubes. p v l Y 3. In a boiler asset forth in claim 2, each serpentine tube'connected to the third portion of ay heater'tube of Y ,oneV set being horizontally interposed between two serpencommunicating witheach other, said shell means Vbeing formed with aV gas discharge port communicating with a portion of said ue space spaced from the portion thereof communicatingwithy said lfurnace space,l vsaid portions of said flue Vspace vjointly constituting r a lpath for thetlow of gas from saidfurnace space to said discharge porty in a predetermined direction; p t 1 Y (c) a distributor system;v

i (d) a collector system upwardly spaced 'from saidV 1 distributory system, said systems being mounted on said shell means and, being separatedby atleast a portion of said boiler space; Y Y

(e) a rst set and a second set of juxtaposed heating tubes extending upwards in said boiler spacey from respective horizontally spaced portions of said dist tributor system, Y .Y p

(l) a rst group of juxtaposediheating tubes'in each set vextending continuously upwards from tine tubes connected tothe third portions ofheater tubes of the vother set. l Y

4. In a water tube boiler,-in combination:

(a) vshell means defining a boiler space therein and havatopportion Vand a bottomportion;V (b) a partition in said boiler space dividing the same into a furnace space and a flue space, said furnace f space and saidflue space having respective portions communicating with eachother, said shell means being formed with a gas discharge port communicating with a portion of said flue `space spacedfrom the portion v thereof communicating with said furnace space, `said portions of said tlue space jointly constituting a path for the flow of gas from said furnace spacev tolsaid discharge port in" a predetermined direction;V V Y I (c) a distributor system; 1'(d),ay collector system upwardly spaced from said 'said shell means and being separated by at least'a portion offsaid boiler space; /f/

(e) Variirst set and a second set of juxtaposed heating tubes extendingY upwards from respective horizontally spacedvportions of said distributor system, the sets being spacedly opposite each other,

(l) thetubesin each set having each three longit'udinally consecutive portions,

'1(2)y a Vfirst portion extending'upward from said i distributing system,

' (3) a second portionextending horizontally from said rst portion toward the rst portions of v y Y the other set, andv (4) a third portion extending upwards from said Vsecond portion to'connect withsaid collector system, v f

(5) said second portions of said heating tubes of one set being vertically offsetfrom the second portions of the heating tubes of the other set, said ysecond portions yjointly constituting said partition4 and being spacedvfrom'each rother for communication between said furnace space and Y y Y saidue space through said partition; f s (fs) a, plurality of U-shaped serpentine -tubes in said f. flue space, vsaid tubes -each extending in a vertical plane and having two end portionsvertically spaced Y Y from each other andA connected to a respective one of said third portions; ,andy p distributor system, saidsystems being mounted onf?r 5 (g) diverting means in each of said third portions between the end portions of the connected serpentine ltube for diverting fluid from said heating tubes to said serpentine tubes.

References Cited bythe Examiner UNITED STATES PATENTS 2,993,481 7/61 Svensson 122-406 6 FOREIGN PATENTS 901,866 11/44 France. 718,275 3 42 Germany. 265,298 3/50 Switzerland.

PERCY L. PATRICK, Primary Examiner.

FREDERICK L. MATTESON, JR., KENNETH W.

SPRAGUE, Examiners. 

1. IN A WATER TUBE BOILER, IN COMBINATION: (A) SHELL MEANS DEFINING A BOILER SPACE THEREIN. SAID SHELL MEANS HAVING A BOTTOM PORTION, A TOP PORTION, AND TWO HORIZONTALLY SPACED OPPOSITE SIDE PORTIONS CONNECTNG SAID BOTTOM PORTION AND SAID TOP PORTION; (B) A DISTRIBUTOR SYSTEM AND A COLLECTOR SYSTEM RESPECTIVELY MOUNTED ON SAID SHELL MEANS ADJACENT SAID BOTTOM PORTION AND SAID TOP PORTION; (C) TWO SETS OF ELONGATED HEATING TUBES CONNECTING SAID SYSTEMS, THE TUBES OF EACH SET BEING SPACEDLY JUXTAPOSED SO AS TO DEFINE INTERSTICES THEREBETWEEN, (1) EACH TUBE HAVING THREE LONGITUDINALLY SUCCESSIVE PORTIONS IN SAID SPACE, THE FIRST PORTIONS OF THE TUBES OF SAID SETS EXTENDING UPWARDS FROM SAID DISTRIBUTOR SYSTEM ADJACENT RESPECTIVE SIDE PORTIONS OF SAID SHELL MEANS,A SECOND PORTION OF EACH TUBE EXTENDING FROM SAID FIRST PORTION THEREOF HORIZONTALLY ACROSS SAID BOILER SPACE TOWARD THE OTHER SIDE PORTION OF SAID SHELL MEANS, AND A THIRD PORTION OF EACH TUBE EXTENDING UPWARD FROM SAID SECOND PORTION ALONG SAID OTHER SIDE PORTION TO CONNECT WITH SAID COLLECTOR SYSTEM, (2) THE TUBES OF EACH SET BEING ALIGNED WITH THE INTERSTICES IN THE OTHER SET; 